Maternal Physiology and Pregnancy Flashcards
List 4 Maternal Glucose metabolism changes that occur
- Reduced blood [Glucose] and [Amino Acids]
- Insulin resistance in second half of pregnancy
- Increased maternal Free Fatty Acids, Ketones, TAG
- Increased insulin release
List the 3 hormones involved in altering Maternal Glucose Metabolism in pregnancy
What do they do?
hPL/ hCS;
- Causes Maternal Insulin Resistance (PRL has a similar role)
Oestrogen;
- Stimulates increase in PRL release
Progesterone;
- Increases appetite in first half of pregnancy
- Diverts glucose into fat synthesis
Overall in pregnancy how do the following change;
- Maternal glucose usage
- Maternal gluconeogenesis
- Mother’s energy source in later pregnancy
Glucose usage- Decreases
Gluconeogenesis- Increases
(Maximises availability of glucose to fetus)
Energy source- Metabolising Peripheral fatty acids
In pregnancy, the mother is said to be in an Immunocompromised state. (Progesterone contributes to this)
Th Fetus is a Hemi-allograft. What does this mean?
- Recognised by maternal immune system
- Incited response isn’t cytotoxic
Pregnancy does not impair respiratory function, but respiratory diseases may be more serious.
Why is this?
Increased O2 requirement of Gestation
How does Respiratory function change in pregnancy?
What hormone causes these changes and how?
- No change in RR
- Significantly increased TV= Increased minute ventilation (rr*tv)
- (Reduced ERV and TLC as well)
- Progesterone acts directly on Respiratory centre, sensitising Chemoreceptors to CO2 changes
How may change in respiratory function appear to patient when pregnant?
- Increased awareness of desire to breathe
- May be interpreted as Dyspnea
In Pregnancy, Cardiac Output needs to be increased.
What are 2 types of ways this is done?
- Volume expansion
- Altered clotting mechanisms
Describe 3 ways Volume expansion occurs
Suggest one possible complication due to Progsterone’s effects
- Increase in plasma volume
- Increase in CO, MAINLY via increased SV
- Increasing Progesterone levels cause Vasodilation-> Drop in TPR-> Drop in mean Arterial Blood Pressure
Hypotension (due to drop in mABP)
By when does BP return to normal?
By Trimester 3 (Low in Trimester 1 and 2)
Via Oestrogen and Progesterone, how is SV increased to raise CO
O: Causes Angiotensinogen release from Liver
O+P: Cause drop in BP and Fluid Volume-> Renin release
- Angiotensin II produced, which causes Vasoconstriction and Aldosterone release
- Aldosterone up-regulates ENaCs, increasing Na + H2O reabsorption
- THUS: Increased BP and Plasma volume
How is Clotting different in Pregnancy?
What can this lead to?
Can this be treated with Warfarin?
- Increased clotting factors and fibrinogen
- Reduced fibrinolysis and anticoagulants
Thromboembolic disease, can’t be treated with Warfarin as it is a Teratogen that can cross the Placenta
What are 3 consequences of cardiovascular changes in pregnancy?
- Increased RAAS activity: Peripheral oedema
- Increase in plasma volume>increase in RBC volume: Dilutional anaemia (Anaemia can also be due to Iron/ Folate deficiency)
- Hypercoagulable state: Increased number of thromboembolic events
How does Renal function change in pregnancy?
Renal blood flow increases to increase GFR to 160% of normal
- Creatinine clearance increases
- Serum urea and creatinine fall
How does Gastrointestinal function change in pregnancy?
Progesterone causes smooth muscle relaxation throughout GI tract;
- Delayed gastric emptying
- Delayed Bowel motility
- Reduced Gallbladder emptying (Possible gallstones)
